Field of the Invention
The present invention relates to a flush toilet, and particularly, to a flush toilet that cleans a bowl using a swirl flow formed by cleaning water flowing down from a rim.
Description of the Related Art
There is conventionally known a flush toilet provided with a so-called open rim structure in which a slit aperture is formed on a bottom surface of a rim water passage in a bowl. Since such a flush toilet cleans the bowl by causing cleaning water to flow down substantially right below from the slit aperture on the bottom surface of the rim water passage, there occurs a problem of a cleaning defect because of a relatively weak cleaning force to the bowl.
On the other hand, as shown in Japanese Patent Unexamined Publication No. 2015-158128 (JP2015-158128A), there is known a flush toilet in which an ascending conduit of discharge trap is formed in a mountain shape in section, a velocity of a water flow on the bottom side of the ascending conduit is increased and a velocity of a water flow on the upper side is decreased. Thereby an entire velocity of the water flows in the ascending conduit is appropriately maintained to cause the cleaning water to smoothly flow without a pressure loss, thus enhancing a cleaning efficiency.